A three-dimensional particle-tracking model has been developed to predict far-field transport of suspended sediment loads resulting from dredging operation. The model was applied to the case study of waterway dredging operation in Asan Bay, Korea in which tidal currents are dominant. Numerical simulations for the transport of suspended sediments with multi-component mixtures of 5 different particle sizes were conducted under the spring and the neap tidal current conditions. The particle streaklines show that fine-grained sediments were transported up to ${sim}20;km$ downstream distance along the bay channel while coarse sediments were deposited immediately in the dredging area. The higher concentration of suspended sediments was found in the main channel of waterways where tidal currents were much stronger in the bay.